var mul_table = [  
        512,512,456,512,328,456,335,512,405,328,271,456,388,335,292,512,  
        454,405,364,328,298,271,496,456,420,388,360,335,312,292,273,512,  
        482,454,428,405,383,364,345,328,312,298,284,271,259,496,475,456,  
        437,420,404,388,374,360,347,335,323,312,302,292,282,273,265,512,  
        497,482,468,454,441,428,417,405,394,383,373,364,354,345,337,328,  
        320,312,305,298,291,284,278,271,265,259,507,496,485,475,465,456,  
        446,437,428,420,412,404,396,388,381,374,367,360,354,347,341,335,  
        329,323,318,312,307,302,297,292,287,282,278,273,269,265,261,512,  
        505,497,489,482,475,468,461,454,447,441,435,428,422,417,411,405,  
        399,394,389,383,378,373,368,364,359,354,350,345,341,337,332,328,  
        324,320,316,312,309,305,301,298,294,291,287,284,281,278,274,271,  
        268,265,262,259,257,507,501,496,491,485,480,475,470,465,460,456,  
        451,446,442,437,433,428,424,420,416,412,408,404,400,396,392,388,  
        385,381,377,374,370,367,363,360,357,354,350,347,344,341,338,335,  
        332,329,326,323,320,318,315,312,310,307,304,302,299,297,294,292,  
        289,287,285,282,280,278,275,273,271,269,267,265,263,261,259];  
var shg_table = [  
         9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,   
        17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,   
        19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,  
        20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,  
        21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,  
        21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,   
        22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,  
        22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,   
        23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,  
        23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,  
        23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,   
        23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,   
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,  
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,  
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,  
        24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24 ];  
  
function stackBlurImage( imageID, canvasID, radius,maindiv )  
{  
              
    var img = document.getElementById( imageID );  
    var canvas = document.getElementById( canvasID );  
    var mainDiv = document.getElementById( maindiv );  
      
     var oMainH = $(mainDiv).height();  
     var oMainW = $(mainDiv).width();  
     var oMainL = $(mainDiv).offset().left;  
     var oMainT = $(mainDiv).offset().top;  
  
     canvas.style.width  = oMainW + "px";  
     canvas.style.height = oMainH + "px";  
     canvas.width = oMainW;  
     canvas.height = oMainH;  
     canvas.style.left = oMainL + "px";  
     canvas.style.top = oMainT + "px";  
      
     var context = canvas.getContext("2d");  
     context.clearRect( 0, 0, oMainW, oMainH );  
  
     context.drawImage( img,oMainL,oMainT,oMainW,oMainH, 0, 0 ,oMainW,oMainH );  
          
  
    if ( isNaN(radius) || radius < 1 ) return;  
      
    stackBlurCanvasRGBA( canvasID, 0, 0, oMainW, oMainH, radius );  
      
}  
  
  
function stackBlurCanvasRGBA( id, top_x, top_y, width, height, radius )  
{  
    if ( isNaN(radius) || radius < 1 ) return;  
    radius |= 0;  
      
    var canvas  = document.getElementById( id );  
    var context = canvas.getContext("2d");  
    var imageData;  
      
    try {  
      try {  
        imageData = context.getImageData( top_x, top_y, width, height );  
      } catch(e) {  
        
        // NOTE: this part is supposedly only needed if you want to work with local files  
        // so it might be okay to remove the whole try/catch block and just use  
        // imageData = context.getImageData( top_x, top_y, width, height );  
        try {  
            netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");  
            imageData = context.getImageData( top_x, top_y, width, height );  
        } catch(e) {  
            alert("Cannot access local image");  
            throw new Error("unable to access local image data: " + e);  
            return;  
        }  
      }  
    } catch(e) {  
      alert("Cannot access image");  
      throw new Error("unable to access image data: " + e);  
    }  
              
    var pixels = imageData.data;  
              
    var x, y, i, p, yp, yi, yw, r_sum, g_sum, b_sum, a_sum,   
    r_out_sum, g_out_sum, b_out_sum, a_out_sum,  
    r_in_sum, g_in_sum, b_in_sum, a_in_sum,   
    pr, pg, pb, pa, rbs;  
              
    var div = radius + radius + 1;  
    var w4 = width << 2;  
    var widthMinus1  = width - 1;  
    var heightMinus1 = height - 1;  
    var radiusPlus1  = radius + 1;  
    var sumFactor = radiusPlus1 * ( radiusPlus1 + 1 ) / 2;  
      
    var stackStart = new BlurStack();  
    var stack = stackStart;  
    for ( i = 1; i < div; i++ )  
    {  
        stack = stack.next = new BlurStack();  
        if ( i == radiusPlus1 ) var stackEnd = stack;  
    }  
    stack.next = stackStart;  
    var stackIn = null;  
    var stackOut = null;  
      
    yw = yi = 0;  
      
    var mul_sum = mul_table[radius];  
    var shg_sum = shg_table[radius];  
      
    for ( y = 0; y < height; y++ )  
    {  
        r_in_sum = g_in_sum = b_in_sum = a_in_sum = r_sum = g_sum = b_sum = a_sum = 0;  
          
        r_out_sum = radiusPlus1 * ( pr = pixels[yi] );  
        g_out_sum = radiusPlus1 * ( pg = pixels[yi+1] );  
        b_out_sum = radiusPlus1 * ( pb = pixels[yi+2] );  
        a_out_sum = radiusPlus1 * ( pa = pixels[yi+3] );  
          
        r_sum += sumFactor * pr;  
        g_sum += sumFactor * pg;  
        b_sum += sumFactor * pb;  
        a_sum += sumFactor * pa;  
          
        stack = stackStart;  
          
        for( i = 0; i < radiusPlus1; i++ )  
        {  
            stack.r = pr;  
            stack.g = pg;  
            stack.b = pb;  
            stack.a = pa;  
            stack = stack.next;  
        }  
          
        for( i = 1; i < radiusPlus1; i++ )  
        {  
            p = yi + (( widthMinus1 < i ? widthMinus1 : i ) << 2 );  
            r_sum += ( stack.r = ( pr = pixels[p])) * ( rbs = radiusPlus1 - i );  
            g_sum += ( stack.g = ( pg = pixels[p+1])) * rbs;  
            b_sum += ( stack.b = ( pb = pixels[p+2])) * rbs;  
            a_sum += ( stack.a = ( pa = pixels[p+3])) * rbs;  
              
            r_in_sum += pr;  
            g_in_sum += pg;  
            b_in_sum += pb;  
            a_in_sum += pa;  
              
            stack = stack.next;  
        }  
          
          
        stackIn = stackStart;  
        stackOut = stackEnd;  
        for ( x = 0; x < width; x++ )  
        {  
            pixels[yi+3] = pa = (a_sum * mul_sum) >> shg_sum;  
            if ( pa != 0 )  
            {  
                pa = 255 / pa;  
                pixels[yi]   = ((r_sum * mul_sum) >> shg_sum) * pa;  
                pixels[yi+1] = ((g_sum * mul_sum) >> shg_sum) * pa;  
                pixels[yi+2] = ((b_sum * mul_sum) >> shg_sum) * pa;  
            } else {  
                pixels[yi] = pixels[yi+1] = pixels[yi+2] = 0;  
            }  
              
            r_sum -= r_out_sum;  
            g_sum -= g_out_sum;  
            b_sum -= b_out_sum;  
            a_sum -= a_out_sum;  
              
            r_out_sum -= stackIn.r;  
            g_out_sum -= stackIn.g;  
            b_out_sum -= stackIn.b;  
            a_out_sum -= stackIn.a;  
              
            p =  ( yw + ( ( p = x + radius + 1 ) < widthMinus1 ? p : widthMinus1 ) ) << 2;  
              
            r_in_sum += ( stackIn.r = pixels[p]);  
            g_in_sum += ( stackIn.g = pixels[p+1]);  
            b_in_sum += ( stackIn.b = pixels[p+2]);  
            a_in_sum += ( stackIn.a = pixels[p+3]);  
              
            r_sum += r_in_sum;  
            g_sum += g_in_sum;  
            b_sum += b_in_sum;  
            a_sum += a_in_sum;  
              
            stackIn = stackIn.next;  
              
            r_out_sum += ( pr = stackOut.r );  
            g_out_sum += ( pg = stackOut.g );  
            b_out_sum += ( pb = stackOut.b );  
            a_out_sum += ( pa = stackOut.a );  
              
            r_in_sum -= pr;  
            g_in_sum -= pg;  
            b_in_sum -= pb;  
            a_in_sum -= pa;  
              
            stackOut = stackOut.next;  
  
            yi += 4;  
        }  
        yw += width;  
    }  
  
      
    for ( x = 0; x < width; x++ )  
    {  
        g_in_sum = b_in_sum = a_in_sum = r_in_sum = g_sum = b_sum = a_sum = r_sum = 0;  
          
        yi = x << 2;  
        r_out_sum = radiusPlus1 * ( pr = pixels[yi]);  
        g_out_sum = radiusPlus1 * ( pg = pixels[yi+1]);  
        b_out_sum = radiusPlus1 * ( pb = pixels[yi+2]);  
        a_out_sum = radiusPlus1 * ( pa = pixels[yi+3]);  
          
        r_sum += sumFactor * pr;  
        g_sum += sumFactor * pg;  
        b_sum += sumFactor * pb;  
        a_sum += sumFactor * pa;  
          
        stack = stackStart;  
          
        for( i = 0; i < radiusPlus1; i++ )  
        {  
            stack.r = pr;  
            stack.g = pg;  
            stack.b = pb;  
            stack.a = pa;  
            stack = stack.next;  
        }  
          
        yp = width;  
          
        for( i = 1; i <= radius; i++ )  
        {  
            yi = ( yp + x ) << 2;  
              
            r_sum += ( stack.r = ( pr = pixels[yi])) * ( rbs = radiusPlus1 - i );  
            g_sum += ( stack.g = ( pg = pixels[yi+1])) * rbs;  
            b_sum += ( stack.b = ( pb = pixels[yi+2])) * rbs;  
            a_sum += ( stack.a = ( pa = pixels[yi+3])) * rbs;  
             
            r_in_sum += pr;  
            g_in_sum += pg;  
            b_in_sum += pb;  
            a_in_sum += pa;  
              
            stack = stack.next;  
          
            if( i < heightMinus1 )  
            {  
                yp += width;  
            }  
        }  
          
        yi = x;  
        stackIn = stackStart;  
        stackOut = stackEnd;  
        for ( y = 0; y < height; y++ )  
        {  
            p = yi << 2;  
            pixels[p+3] = pa = (a_sum * mul_sum) >> shg_sum;  
            if ( pa > 0 )  
            {  
                pa = 255 / pa;  
                pixels[p]   = ((r_sum * mul_sum) >> shg_sum ) * pa;  
                pixels[p+1] = ((g_sum * mul_sum) >> shg_sum ) * pa;  
                pixels[p+2] = ((b_sum * mul_sum) >> shg_sum ) * pa;  
            } else {  
                pixels[p] = pixels[p+1] = pixels[p+2] = 0;  
            }  
              
            r_sum -= r_out_sum;  
            g_sum -= g_out_sum;  
            b_sum -= b_out_sum;  
            a_sum -= a_out_sum;  
             
            r_out_sum -= stackIn.r;  
            g_out_sum -= stackIn.g;  
            b_out_sum -= stackIn.b;  
            a_out_sum -= stackIn.a;  
              
            p = ( x + (( ( p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1 ) * width )) << 2;  
              
            r_sum += ( r_in_sum += ( stackIn.r = pixels[p]));  
            g_sum += ( g_in_sum += ( stackIn.g = pixels[p+1]));  
            b_sum += ( b_in_sum += ( stackIn.b = pixels[p+2]));  
            a_sum += ( a_in_sum += ( stackIn.a = pixels[p+3]));  
             
            stackIn = stackIn.next;  
              
            r_out_sum += ( pr = stackOut.r );  
            g_out_sum += ( pg = stackOut.g );  
            b_out_sum += ( pb = stackOut.b );  
            a_out_sum += ( pa = stackOut.a );  
              
            r_in_sum -= pr;  
            g_in_sum -= pg;  
            b_in_sum -= pb;  
            a_in_sum -= pa;  
              
            stackOut = stackOut.next;  
              
            yi += width;  
        }  
    }  
      
    context.putImageData( imageData, top_x, top_y );  
      
}  
  
function BlurStack()  
{  
    this.r = 0;  
    this.g = 0;  
    this.b = 0;  
    this.a = 0;  
    this.next = null;  
}  